Hello folks, I'm working on a conversion of my moped from the SLA to LiFePO4. Everything has gone well except accelation and range. The moped is considerably worse than before. I want to know if it is normal for a 1500W hub motor moped to drop the voltage from 57.8V to approximately 42V when starting from a flat surface? The controller is set to not pull more than 30A and 36,8V from the battery. I have charge the pac about 15 times since I installed it. The voltage of each cell is 3.62V-3.67V and 3.05V-3.16V after a 20 min drive. I will make a log of each cell during drive when time will be on my side. My guess is that the controller holds back when the voltage drops.

Looks as if your battery is too small! Try doubling the capacity, to at least 40 AH. The cells you are using apparently do not take well to high-rate discharge, so adding another identical pack in parallel may fix the problem.